The invention relates to a shaft cooling system for a tool motor spindle, comprising a rotating shaft, a static lance and at least one cooling circuit having a coolant intake and a coolant outlet.
The tool motor spindles are operated at high rotational speeds. These high rotational speeds make great demands on the bearing arrangement via which the spindle is mounted, so as to be rotatable about its spindle axis, in the spindle housing. In particular, the bearing friction must be reduced to an absolute minimum, in order to reduce the generation of heat and the wear. It is therefore necessary to provide a shaft cooling system.
Such a shaft cooling system is described in WO 2006/018394 A1. Described therein is a spindle device comprising a shaft device and a cooling device. The cooling device has at least one convection gap, via which a substantial portion of dissipated heat can be removed from the shaft device in targeted fashion.
Additionally known are tool motor spindles that are externally cooled for the purpose of removing the dissipated power.
The disadvantages that exist in the case of these known shaft cooling systems consist, in particular, in that, owing to the insufficient cooling action, an insufficiently reduced shaft growth occurs as a result of the thermal expansion.
The object of the invention therefore consists in proposing a shaft cooling system that, on the one hand, reduces a longitudinal growth of the shaft to a minimum and, on the other hand, owing to the smallness of the longitudinal growth, ensures a high measurement accuracy in the dimensional checking of the workpiece.